– Relapse-free/progression-free survival for NKTR-255 plus CD19-22 CAR-T cell therapy at 12 months was double that of historical controls (67% vs 38%) –

– Eight of nine patients achieved complete remission, all without detectable MRD –

SAN FRANCISCO, Oct. 17, 2024 /PRNewswire/ -- Nektar Therapeutics (NASDAQ:NKTR) today announced the publication of the first clinical data from a Phase 1 study evaluating NKTR-255 in combination with an autologous bispecific chimeric antigen receptor (CAR)-T cell therapy targeting CD19 and CD22 in patients with relapsed or refractory B-cell acute lymphoblastic leukemia (B-ALL) in Blood, the peer-reviewed medical journal of the American Society of Hematology.

NKTR-255 is a novel IL-15 receptor agonist currently being studied in clinical trials in combination with cellular therapies and immune checkpoint inhibitors. NKTR-255 has shown in previous clinical studies that it can proliferate a range of immune cells and augment lymphocyte trafficking.1,2

The data published in Blood showed favorable efficacy with eight out of nine patients (89%) whom successfully received CAR19-22 followed by NKTR-255 achieving measurable residual disease (MRD) negative remission. The study further demonstrated that, at 12 months, relapse-free/progression-free survival for NKTR-255 in combination with the CD19-22 CAR-T cell therapy was double that of historical controls (67% vs 38%).